INTRODUCTION
Heterocyclic compounds containing nitrogen atoms are considered to be one of the most effective antimicrobial drugs used as either single agents or in combination for cancer therapy . Some benzotriazole derivatives have shown antiinflammatory
properties . Touami et al reported that the conjugates of benzotriazole derivative photonucleases and DNA minor groove binders exhibit enhanced cleavage efficiency and unique selectivity. It has been proposed that the benzotriazole derivatives have the effect on cancer development . Sparatore and Sparatore reported that 2-(4-(Dialkyl amino alkoxy) phenyl) benzotriazoles and N-oxides works as thromboxane A2 antagonists and as hypocholesterolemic agents, platelet aggregation inhibitors , where as benzotriazole carboxylic acid or ester derivatives were found to be effective in the treatment of metabolic related disorders including atherosclerosis, coronary heart disease and type 2 diabetes . Biagi et al. reported that 5- (substituted) benzotriazoles and triazolyl benzotriazoles as potential potassium channel activators.

The ultrasound irradiation technique has been increasingly used in organic synthesis for last three decades. A large number of organic reactions have been carried out in higher yield, shorter reaction time and milder condition under ultrasound irradiation . It is well known that ultrasonic irradiation to a liquid phase reaction accelerates the chemical reaction and creates a special reaction field for the preparation of various materials . There is a growing awareness that the design of synthetic or chemical processes should follow the basic principles of green chemistry to reduce risks to humans and the environment. Largescale use of organic solvents in synthesis causes environmental hazards . There were several advantages of performing syntheses in solvent-free media, such as, short reaction time, increased safety, and low cost . Recently, a few papers reported modern synthetic protocols where solvent-less condition have been used . Finally, herein we wish to report the anti-bacterial activity of some newer 1,2,3 - benzotriazole derivatives synthesized by ultrasonication in solvent - free conditions.

Benzotriazole (BTA) is a heterocyclic compound containing three nitrogen atoms, with the chemical formula C6H5N3. This aromatic compound is colorless and polar and can be used in various fields.

Applications
Benzotriazole has been known for its great versatility. It has already been used as a restrainer in photographic emulsions and as a reagent for the analytical determination of silver. More importantly, it has been extensively used as a corrosion inhibitor in the atmosphere and underwater. Also, its derivatives and their effectiveness as drug precursors have been drawing attention. Besides all the application mentioned above, the BTA can be used as antifreezes, heating and cooling systems, hydraulic fluids and vapor phase inhibitors as well.

Corrosion inhibitor
Benzotriazole is an effective corrosion inhibitor for copper and its alloys by preventing undesirable surface reactions. It is known that a passive layer, consisting of a complex between copper and benzotriazole, is formed when copper is immersed in a solution containing benzotriazole. The passive layer is insoluble in aqueous and many organic solutions. There is a positive correlation between the thickness of the passive layer and the efficiency of preventing corrosion. BTA is used in conservation, notably for the treatment of bronze disease. The exact structure of the copper-BTA complex is controversial and many proposals have been suggested.

Drug precursor
Benzotriazole derivatives have chemical and biological properties that are versatile in the pharmaceutical industry. Benzotriazole derivatives act as agonists for many proteins. For instance, vorozole and alizapride have useful inhibitory properties against different proteins and benzotriazole esters have been reported to work as mechanism-based inactivators for severe acute respiratory syndrome (SARS) 3CL protease. The methodology is not only limited to heterocyclization but was also successful for polynuclear hydrocarbons of small carbocyclic systems.
Trazolopride & Tribendilol are other benztriazole examples of drugs.
Considering the need for discovery of new antifungal drugs with greater potency and broader spectrum of activity, a new series of 5-substituted benzotriazole derivatives were designed, through structure based design, as inhibitors of fungal cytochrome P450 lanosterol 14-α demethylase. These were further optimized by a combination of iterative medicinal chemistry principles and molecular docking. Based on the best docking scores, some benzotriazole derivatives were synthesized and characterized by IR, (1)H NMR and MS/MS. The molecules were evaluated for their antifungal action against Candida albicans by cup plate method and ergosterol quantification method by UV spectroscopy. Reasonably good correlation between docking scores and antifungal activity were observed. The computational predictions were in consensus with the experimental results.